Standard Arduino Nanos can be used for many purposes, but they do not feature wireless capabilities. Somehow, though, Hari Wiguna’s Arduino psychic system is apparently able to pass data between two of them. No external communication hardware is implemented, yet one Nano is able to recognize when a random number chosen on the other Nano setup is input via an attached keypad.
As noted by Wiguna, it’s easier shown than explained, and you can see this techno-magic trick in action in the first clip. How things work is revealed in the second video, but can you guess how it’s done?
Code is available in the project’s write-up, which may provide some insight, however the hardware schematics – that appear to be accurate – will likely leave you amazed!